so i did a search and i saw the same answers to this question every time. the same people too, and they always go a little of track. I wanted to know what people think about a locked welded rear diff. this would be for the road course only and NOT for street or drag!!
Is this a stupid idea or could it work out to make a great driver faster? (not me )

 

you do NOT want a welded diff in a road racing application, or anywhere you have to turn a lot! A limited slip would be great for the corners, but thats some more $$$. A welded diff is only useful for drag racing, or for drifting as its easy to break the back end loose around corners.

 

what would a welded diff do on the street?..... i have been contimplating using some 4.77 gears out of a kia sportage (http://mazspeed.bcrx7.com/forum/thre...rdid=11&page=1)and welding the diff to have posi... this will be on a street/strip car... im just wondering what will happen on the street?.... mad fishtailing or what?

-greg

 

Why would you get in to throw 4.777 gears and just to weld the spider gears?Dont be half *** and just get a LSD.

No one knows if the Kias actually work ..the guy hasnt posted back on both forums..

In theory it should if it works in a Miata and Miata works on a 7.

 

A welded diff on the street will be great on the straight line, but SUCK *** in any corner. Can you say HOP HOP HOP as the inside rear tries to keep the exact same speed as the outside rear?? lol, it will be VERY annoying, unless you plan on sliding around every corner. Tire wear will suffer pretty bad as well. I would highly recommend an LSD if you want to retain any streetability.

 

hmmm.. would an lsd give the posi effect at the track?

-greg

 

Limited slip allows one wheel to slip a certain amount, enough to not cause problems with turning, but they wont allow one wheel to spin freely. Its the best of both worlds, traction coming out of the corner, no "one wheel peel", without the hopping of the welded diff.

 

one wheel peel.. i like that... i usualy call it "one tire fire"

hehe so an LSD will give me traction to both tires while drag racing and say doing a "powerbrake" both tires will spin... and then taking corners it will act as an open diff?

-greg

 

A LSD is the same as POSI traction,POSI is the GM name for it and trademark.

You DONT want to be taking a corner with a welded spidergears going fast..It will be ok for straight runs at the track ,but eventually it will brake

 

yes, exactly

 

sweet...
thanks man

also.. i have a gsl-se parts car.. but u jacked the car up and turned the passenger side wheel and the drivers side didnt turn... then i turned the drivers side and the passenger side turned opposite....

is it safe to say the lsd is shot?

also i notices a small puddle of oil right below the pumpkin... should i even waste my time swapping this rearend?...

-greg

 

if anything i will swap the rearend because i already swapped the front suspension and rolling 15 inch wheels in the front and the stock 13;s in the back dosent look that good...lol

if the lsd is shot it will still act as an open diff right?

-greg

 

I was at a autocross once and there was a first gen there, I think it was spec7 (maybe, i didnt ask) but it had welded spider gears.

In a racing application all corners are taken at very high speed, there is minimal weight on the inside tire. So I doubt hopping would be a problem

 

See this is what I was thinking would happen too. Ao forcing the car to spinat the same rate will give perdictability and exit speed. no? Isn't this more like a
2way Lsd ?

 

In road racing or autocrossing the locked rear end is the way to go.......but.....when you come off the track or throught the pits, you get tons of "tire jumping". You will eventually break the welds....we did this in the 80s and 90s when there was no good LSD or torsen unit available for the 1st gen. It is best to have the rear locked in road racing but the life is very short....sssoooo... the best option is the racing LSD or the torsen unit. Just stand in the pits when a SCCA TransAm car comes into the pits, the tires jump like crazy!!!! I believe, at least they used to, have locked rearends. my .02

 

about the only people i know who weld the diff is somebody doing a demolition derby and doesn't care about tire wear or cornering. It works rather well for that application

 

i would say welded gears would be alright for road racing. but ill tell you what... the LSD on my dads car was just rebuilt and this thing is VERY tight. i cant imagine a welded diff would help much more than a brand new rebuilt LSD. my dad even put the slicker fluid in for LSD applications and its still very tight.

 

huh, what model car and what lsd... i have a se with stock lsd

 

I had a friend with spot welded spider gears on both sides, not welded together though, he's got a 5.0 and blew the rear end in a matter of weeks (but he has torque), it blew when he was just driving normal too.